The biocidal properties of copper (II) salts are known. For example copper (II) sulphate pentahydrate is widely used as an agricultural fungicide, algicide, bactericide and herbicide. Further, it is known to apply the biocidal properties of copper (II) salts to treat water bodies. However, at elevated levels, copper (II) salts generally, and copper (II) sulphate pentahydrate in particular, are toxic to humans. On the other hand, if the levels of copper (II) salts are too low the biocidal effect is compromised.
Accordingly, when using a copper (II) salt to treat a body of water, it is extremely important that the copper (II) ions be evenly distributed throughout the body of water, at an appropriate concentration. A concentration of copper (II) ions between 2 and 10 parts per million is effective in controlling most bacteria and algae. Substantially lower levels of 0.5 to 1 parts per million are effective in inhibiting the growth of some susceptible species. Concentrations of copper (II) ions of up to 2 parts per million are not toxic to almost all plants and animals over extended periods of time. Levels of 10 parts per million are tolerated by most plants and animals over relatively short periods of time.
It is one object of the present invention to provide a biocidal composition that facilitates the provision of appropriate levels of copper (II) throughout a water body. It is a further object of the present invention to provide a method for production of the biocidal agent, and a method for application of the biocidal agent to a water body.
The preceding discussion of the background to the invention is intended to facilitate an understanding of the present invention. However, it should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia as at the priority date of the application.
Throughout the specification, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
Throughout the specification, unless the context requires otherwise, the phrase “water body” or variations such as “water bodies” will be understood to include bores, wells, water pumps, reservoirs, dams, lakes, water pipes, reticulation systems, and the like.